This volume presents a timely snapshot of the state of helio- and asteroseismology in the era when SOHO/MDI is about to be replaced by SDO/HMI and CoRoT is yielding its first long-duration light curves of thousands of stars. This Topical Issue of Solar Physics is inspired by two seminal conferences, HELAS II and SOHO19/GONG 2007, and was open for general submission on the core topics of these conferences. Three papers describing the current status of asteroseismology, global helioseismology, and local helioseismology were specially commissioned for the volume, and these set the context for the other contributions.